1. Field of the Invention
The present invention relates to a method of producing an ink jet recording head that discharges ink to record and an ink jet recording head produced by the method.
2. Related Background Art
An ink jet recording device is integrally or separately provided as an output terminal of an information processing apparatus such as a word processor, computer, and the like, and also, the ink jet recording device is widely used in a copy machine combined with an information reading device or the like, a facsimile apparatus having an information transmitting and receiving function, a printing machine for printing a character etc. to a cloth, and the like. This ink jet recording device has a feature that a high-definition image can be recorded at a high speed by discharging ink from a discharge port as fine droplets.
Particularly, a type of an ink jet recording device that uses an electrothermal converting member as an energy generator which generates energy which is utilized for discharging ink, and discharges ink by utilizing the ink bubbling generated with the thermal energy which is generated by the electrothermal converting member is suitable for high-definition properties of images, high speed recording properties, miniaturization of the recording head and device, and also coloring of images. Therefore, such type ink jet recording device have been recently noted.
An ink jet recording head which is used in an in jet recording device is usually provided with a plurality of discharge ports. The ink jet recording head is hereinafter referred to as merely a "head". Each electrothermal converting member, which generates thermal energy, which is utilized for discharging ink respectively from the discharge ports, is provided on a substrate, with the electrothermal converting member corresponding to each of ink paths. The electrothermal converting member is mainly constructed with exothermic resistors, electrode wiring for supplying the resistors with electric power, and insulating protective films.
The head often has a basic structure connected a substrate provided with electrothermal converting members to an ink paths-formed top plate. In each ink flow path included in the ink path, the discharge port and the opposite end are communicated with a common ink chamber. In this common ink chamber is stored ink which is supplied from an ink tank. A plurality of ink flow paths and the common ink chamber will be integrally referred to as an "ink path" later.
Ink supplied to the common ink chamber is led to each of the ink flow paths and held near the discharge port while forming a meniscus. Thermal energy generated is utilized by selectively driving an electrothermal converting member at this state, to heat rapidly ink on a heat surface to boil it. After that, the ink is discharged from the discharge port.
One conventional example of methods of producing such head is described in U.S. Pat. No. 5,030,317. FIGS. 1A to 1F are schematic perspective views for explaining the steps of the method. As shown in FIG. 1A, on an ink path formation portion on a substrate 21 provided with electrothermal converting members 27 each respectively arranged so as to correspond an ink path, is provided a solid layer 28 made of a resin having, for example, a positive type photosensitive property. Then, as shown in FIG. 1B, on thus obtained structure is formed a layer made of a material to be set or cured with an active energy line, which material will be an ink path wall forming member 22. Then, as shown in FIG. 1C, on the obtained structure is laminated a top plate 24 provided with a recess 29 communicated with an ink supply port 26. After that, as shown in FIG. 1D, a photo-mask 32 is provided on a portion which corresponds to a common ink chamber, an active energy line is irradiated in the arrow direction, and a portion of the material to be set with an active energy line is set. Then, as shown in FIG. 1E, a solid layer removing liquid is introduced in a direction shown with arrows therein, from the ink supply port 26 and the like, to remove the solid layer 28. Thus, as shown in FIG. 1F, an ink path which is communicated with a discharge port 33.
However, by such method, a variance of connecting strength between the layer made of the material set with the active energy line, which will be the ink path forming member 22, and the top plate is generated. Thus, a slight gap therebetween is formed and ink is leaked therefrom, and further, the strength and durability of the head itself are deteriorated.